Issue No.01 - January (1970 vol.19)
Harry C. Andrews , ITT Electro-Physics Laboratories, Inc., Hyattsville, Md.; Department of Electrical Engineering, University of Southern California, Los Angeles, Calif. 90007.
Kenneth L. Caspari , ITT Electro-Physics Laboratories, Inc., Hyattsville, Md.
A technique is presented to implement a class of orthogonal transformations on the order of pN log<inf>p</inf> N operations. The technique is due to Good  and implements a fast Fourier transform, fast Hadamard transform, and a variety of other orthogonal decompositions. It is shown how the Kronecker product can be mathematically defined and efficiently implemented using a matrix factorization method. A generalized spectral analysis is suggested, and a variety of examples are presented displaying various properties of the decompositions possible. Finally, an eigenvalue presentation is provided as a possible means of characterizing some of the transforms with similar parameters.
Harry C. Andrews, Kenneth L. Caspari, "A Generalized Technique for Spectral Analysis", IEEE Transactions on Computers, vol.19, no. 1, pp. 16-25, January 1970, doi:10.1109/TC.1970.5008895